Control means and method for charging a vehicle

ABSTRACT

Embodiments of the present invention provide control means for a vehicle, the control means being operable to control charging of tractive energy storage means of the vehicle, the control means being configured to allow charging of the energy storage means in dependence on a location of the vehicle and a time of day, wherein if the location of the vehicle corresponds to one or more prescribed locations the control means is operable to permit charging only during one or more prescribed periods of the day.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/419,261, filed Feb. 3, 2015, which itself is a 35 U.S.C. §371national stage application of PCT Application No. PCT/EP2013/066510,filed on Aug. 6, 2013, which claims priority from Great Britain PatentApplication No. 1213918.4 filed on Aug. 6, 2012, the contents of whichare incorporated herein by reference in their entireties. Theabove-referenced PCT International Application was published in theEnglish language as International Publication, No. WO 2014/023747 A1 onFeb. 13, 2014.

FIELD OF THE INVENTION

The present invention relates to charging of energy storage means of amotor vehicle. In particular but not exclusively the present inventionrelates to control means for controlling charging of energy storagedevices for powering propulsion motors in so-called plug-in electricvehicles and hybrid electric vehicles, and to a corresponding method.

BACKGROUND

It is known to provide a plug-in electric vehicle (PEV) or plug-inhybrid electric vehicle (PHEV) having a battery that may be charged whenthe vehicle is connected to a charging station. Charging stations aretypically provided with a cable and charging plug which may be connectedto a corresponding socket of the vehicle. In some countries, the cost ofa given unit of electricity depends on the time of day, the cost beinghigher at certain times of day (such as during normal working hours)compared with other times. It is desirable to take advantage of reducedelectricity costs where possible in order to reduce an overall runningcost of a PEV or PHEV.

STATEMENT OF THE INVENTION

Embodiments of the invention may be understood with reference to theappended claims.

Aspects of the present invention provide an apparatus, a vehicle and amethod.

In one aspect of the invention for which protection is sought there isprovided control means for a vehicle, the control means being operableto control charging of tractive energy storage means of the vehicle forpowering one or more electric propulsion motors, the control means beingconfigured to allow charging of the energy storage means in dependenceon a location of the vehicle and a time of day, wherein if the locationof the vehicle corresponds to one or more prescribed locations thecontrol means is operable to perform charging during one or moreprescribed periods of the day.

It may be that the controller is operable to permit charging only duringone or more prescribed periods of the day.

The control means may comprise a control unit or controller, for examplein the form of a processor, microcontroller or electronic control module(ECU).

Advantageously the control means may be arranged wherein if the locationof the vehicle does not correspond to one or more prescribed locationsthe control means is operable to perform charging irrespective of thetime of day.

The control means may be operable to allow a user manually to input datacorresponding to an identity of the one or more prescribed periods ofthe day when charging may be performed at the one or more prescribedlocations.

The control means may be operable to access data corresponding to anidentity of the one or more prescribed periods of the day when chargingmay be performed at the one or more prescribed locations.

The control means may be arranged to access data in respect of the oneor more times of day during which charging may be performed via oneselected from amongst a wireless internet connection, a mobiletelecommunications network and a portable data storage device.

The control means may be arranged to receive data indicative of alocation of the vehicle.

Optionally the control means comprises means for determining a locationof the vehicle.

Advantageously the control means may be operable to charge the energystorage means to a prescribed value of state of charge over one or moretime periods determined responsive to data in respect of an expecteddeparture time of the vehicle, the control means being configured tooptimise charging to the prescribed value by charging the energy storagemeans for as long as possible during the one or more prescribed periodsprior to the expected departure time.

Thus if the control means is able to control charging of the energystorage means such that the energy storage means is chargedsubstantially to the prescribed level only during the one or moreprescribed periods the control means does so. However if there isinsufficient time available before the expected departure time to chargeonly during the one or more prescribed periods the control meanscontrols charging such that charging takes place for as long as possibleduring the one or more prescribed periods, the balance of charging beingperformed outside of such a period.

This feature has the advantage that a vehicle operator may take fulladvantage of reduced energy tariffs whilst at the same time ensuringthat the state of charge of the energy storage means is sufficient forthe next journey.

Advantageously the control means may be operable to receive an inputcorresponding to an expected departure time of the vehicle from anoperator of the vehicle.

Advantageously the control means may be operable to receive the inputcorresponding to expected departure time by means of input means, theinput means optionally being one selected from amongst a control buttonand a touchscreen.

The control means may be operable to determine an expected departuretime responsive to historical data in respect of vehicle departuretimes, optionally vehicle departure times from a given location, furtheroptionally vehicle departure times as a function of day of the week.

The control means may be operable to allow a user manually to overridethe controller, such that when the location of the vehicle correspondsto a prescribed location the controller performs charging during anon-prescribed period of the day.

In a further aspect of the invention for which protection is soughtthere is provided a motor vehicle comprising control means according tothe preceding aspect.

In a still further aspect of the invention for which protection issought there is provided a method of controlling by control meanscharging of energy storage means of a vehicle for storing energy topower one or more electric propulsion motors, the method comprising:

-   -   determining by the control means whether a location of the        vehicle corresponds to a prescribed location;    -   if the location of the vehicle does correspond to one or more        prescribed locations, the method comprising performing by means        of the control means charging of the storage means during one or        more prescribed periods of the day.

In a further aspect of the invention for which protection is soughtthere is provided control means for a vehicle having energy storagemeans for storing energy to power one or more electric propulsion motorsof the vehicle, the control means being configured to allow charging ofthe energy storage means in dependence on a location of the vehicle anda current value of an electricity tariff, wherein if the location of thevehicle corresponds to one or more prescribed locations the controlmeans is operable to perform charging during one or more periods forwhich the current value of electricity tariff corresponds to aprescribed one or more values.

The prescribed one or more values of electricity tariff may correspondto an off-peak tariff.

In some embodiments a vehicle is provided that may be consideredautomatically to select to charge the vehicle during a period of the daycorresponding to an off-peak tariff in respect of the cost ofelectricity.

In an aspect of the invention for which protection is sought there isprovided control means for a vehicle having energy storage means forstoring energy to power one or more electric propulsion motors of thevehicle, the control means being configured to allow charging of theenergy storage means in dependence on a current value of an electricitytariff, wherein the control means is operable to permit charging onlyduring one or more periods for which the current value of electricitytariff corresponds to a prescribed one or more values.

Advantageously the control means may be operable to allow charging ofthe energy storage means in further dependence on a location of thevehicle, the control means being operable to allow charging independence on the current value of electricity tariff if the location ofthe vehicle corresponds to one or more prescribed locations.

Within the scope of this application it is envisaged that the variousaspects, embodiments, examples and alternatives set out in the precedingparagraphs, in the claims and/or in the following description anddrawings, and in particular the individual features thereof, may betaken independently or in any combination. Features described withreference to one embodiment are applicable to all embodiments, unlesssuch features are incompatible.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described, by way of exampleonly, with reference to the accompanying figures in which:

FIG. 1 shows a plug-in hybrid electric vehicle (PHEV) according to anembodiment of the invention connected to a recharging station; and

FIG. 2 is a flow chart illustrating a method of operation of a PHEVaccording to an embodiment of the invention.

DETAILED DESCRIPTION

FIG. 1 shows a PHEV 101 according to an embodiment of the inventionconnected to a recharging station 140 by means of a cable 145. Thevehicle 101 has a charge controller 130 that controls charging of abattery 120 of the vehicle 101 when the vehicle 101 is connected to acharging station 140. The battery 120 stores charge for powering anelectric propulsion motor 125.

The vehicle has a central controller 110 that is operable to provide anover-ride control signal to the charge controller 130. If the centralcontroller 110 provides the over-ride control signal to the chargecontroller 130 the charge controller 130 inhibits charging of thebattery 120 even when the vehicle 101 is connected to a charging station140.

In the embodiment of FIG. 1 the central controller 110 is operable torequest a user to input data in respect of one or more prescribedlocations of the vehicle 101 at which charging of the battery 120 is tobe limited to one or more prescribed periods of the day. In other words,when the vehicle is at a prescribed location, charging of the battery120 is to be permitted only during one or more prescribed periods oftime. The central controller 110 is arranged to provide a graphical userinterface (GUI) to a user via a touch screen 115 in order to allow thisdata to be entered.

Thus the user (such as a driver) may be invited to input data to thecontroller 110 via the touch screen 115 corresponding to (1) one or morelocations at which charging of the battery 120 is to be limited to oneor more prescribed periods of the day, and (2) one or more periods of aday when charging is to be permitted.

The user may therefore input to the controller 110 data identifying theone or more periods of time during a day for which the cost ofelectrical power (i.e. the electricity tariff) is reduced or at aminimum. These are the periods during which charging of the battery isto be permitted. The central controller 110 stores data corresponding tothe one or more prescribed locations and the one or more prescribedperiods in a memory thereof.

In use, if the vehicle 101 is connected to a charging station 140 at oneof the one or more prescribed locations, the central controller 110inhibits charging of the battery 120 except during the one or moreprescribed periods of time. During the one or more prescribed periods,the controller 110 does not over-ride charging of the battery 120.

In some embodiments, if the battery 120 is not fully charged when aprescribed charging period ends, the controller 110 provides anover-ride signal to the charge controller 130 and further charging ofthe battery 120 is suspended until the next prescribed period begins. Insome embodiments however, the central controller 110 and/or chargecontroller 130 may be configured to permit charging to continue untilthe battery 120 is fully charged, once charging has been started. Insome embodiments, the controller 110 may be operable to determinewhether the battery 120 may be sufficiently charged during the nextprescribed period. If the controller 110 determines that the battery 120cannot be sufficiently charged during this period, the controller 110may commence charging in advance of the prescribed period so as toenable the battery 120 to be charged sufficiently by the end of theprescribed period. Other arrangements are also useful.

It is to be understood that because reduced electricity tariffs aretypically enjoyed at night, a typical prescribed location set by a usermay be the home of the user since the vehicle 101 is likely to be parkedat home overnight. The user will therefore enjoy the benefit of reducedvehicle running costs because charging of the battery 120 takes place atnight when the electricity tariff is lower.

FIG. 2 is a flow chart illustrating a method of operation of the PHEV101 of the embodiment of FIG. 1. At step S101 the vehicle 101 is parkedin a standby mode. At step S103 the central controller 110 determineswhether the vehicle 101 is connected to a recharging station 140. If thevehicle 101 is not connected to a recharging station 140 then at stepS105 no action is taken and the controller 110 continues to checkwhether the vehicle 101 is connected to a recharging station 140.

If at step S103 the controller 110 determines that the vehicle 101 isconnected to a recharging station 140 the method continues to step S107.At step S107 the controller 110 checks the location of the vehicle 101by reference to data received by the controller 110 from a locationdetermination device 112. In the embodiment of FIG. 1 the locationdetermination device 112 is a global satellite positioning system (GPS)device 112. Other location determination devices are also usefulincluding devices that determine location using a cellulartelecommunications network.

At step S109 the controller 110 determines whether the vehicle 101 is ata prescribed location an identity of which has been previously input tothe controller 110 by a user. The prescribed location is a location forwhich charging of the battery 120 is to be limited to one or moreprescribed periods of time of a day. If the controller 110 determines atstep S109 that the vehicle 101 is not located at a prescribed locationthe method continues at step S111. At step S111 the controller 110 doesnot over-ride charging of the battery 120 by the charge controller 130.

At step S111 the charge controller 130 is configured to determinewhether charging of the battery 120 is required based on the state ofcharge of the battery 120. If charging is required then the chargecontroller 130 commences charging of the battery 120. In somealternative embodiments the charge controller 130 determines whethercharging of the battery 120 is required whilst the vehicle 101 is instandby mode at step S101, and only proceeds to step S107 if the vehicle101 is connected to a recharging station 140 and charging of the battery120 is required.

If at step S109 the controller 110 determines that the vehicle islocated at a prescribed location for which charging is to be limited toone or more prescribed periods of time of day, the method continues tostep S113. At step S113 the controller 110 determines whether the timeof day corresponds to one or more prescribed periods of time set by auser. The prescribed periods are set by the user to correspond toperiods of time for which the electricity tariff is reduced, i.e.‘off-peak’ periods of time. Thus, if the current time is between an offpeak tariff start time Off_Peak_Start_Time and an off-peak tariff endtime Off Peak_Stop_Time the method continues to step S111 at whichcharging of the battery 120 is permitted. However if the current time isnot within the off-peak period the method continues to step S113.

In some embodiments the controller 110 is configured to accessautomatically a source of data in respect of one or more periods of aday for which a reduced tariff is payable for electrical power, and touse this information to determine the one or more prescribed periods.

The controller 110 may be configured to take into account days such asweekends and/or public holidays when the start and end times of one ormore reduced tariff periods such as an off-peak tariff period maychange.

In some embodiments the controller 110 may be arranged to access data byany other required method. In some embodiments the controller 110 mayaccess data transmitted by a utility provider over a powerline. The datamay for example indicate a current tariff for electricity drawn from thepowerline. The controller 110 may be configured such that when thevehicle 101 is at one of the one or more prescribed locations, chargingis permitted only for a selected one or more tariffs, or when a tariffis at or below a threshold value. Other arrangements are also useful.

In some embodiments the controller 110 is operable to allow a user toinput an expected departure time of the vehicle being a time at whichthe next journey is expected to commence. Responsive to such an inputthe controller 110 may be arranged to ensure that the battery 120 ischarged to a required value in advance of the expected departure time.The required value may correspond to a substantially fully chargedbattery 120. Alternatively or in addition, in some embodiments thecontroller 110 may be operable to allow a user to provide an indicationof a state of charge they require the battery to achieve, such as 50%,75%, 100% or any other suitable value. In some embodiments thecontroller 110 may be operable to allow a user to provide an indicationof a range (or distance) that the vehicle may be required to be capableof traveling in order to make its next journey, the controller 110 beingarranged to ensure that sufficient charge is available for the expectedrequired range.

The controller 110 may be arranged to ensure that advantage is taken ofany reduced tariff available during the period between the time at whichthe user connects the vehicle 101 to a charging source and the departuretime itself. If no such reduced tariff is available in that period thecontroller 110 may be configured immediately to commence charging of thebattery 120 in order to ensure that the battery 120 is charged to therequired value. This has the advantage that if the departure time isbrought forward, a risk that the battery 120 has insufficient charge forthe journey may be reduced.

If a period of reduced tariff is available before the estimateddeparture time, the controller 110 is arranged to maximise the amount oftime for which charging takes place during the period of reduced tariff.Thus if the amount of time for which charging is required to take placeexceeds the length of the period of reduced tariff, the controller 110is arranged to ensure that charging takes place throughout any one ormore periods of reduced tariff prior to commencement of the journey andeither to (1) commence starting of charging before a period of reducedtariff begins; (2) continue charging after a period of reduced tariffends; or (3) commence charging before a period of reduced tariff beginsand continue charging after the period of reduced tariff ends. Otherarrangements are also useful.

Thus it is to be understood that the controller 110 may adjust a startand/or end time of a charging period with respect to a period of reducedtariff in order to ensure that a battery 120 is sufficiently chargedbefore an expected departure time of a vehicle 101.

Embodiments of the invention have the advantage that user enjoyment of avehicle may be enhanced by reducing a cost of ownership of a vehicle.Furthermore, because charging in off peak periods is favoured, an impactof increasing numbers of PEV and PHEV vehicles on an electricity supplynetwork may be mitigated. Thus, by favouring off-peak periods, an amountof electricity demanded from the electricity supply network during peakperiods when demand for power from businesses and industry is high isreduced. Accordingly, a need to upgrade the supply network in order todeliver increased electrical current to meet the combined demand may bereduced or substantially eliminated.

The invention includes embodiments in which a vehicle is charged usinginductive coils, as well as to other methods of charging which do notrequire a plug.

Throughout the description and claims of this specification, the words“comprise” and “contain” and variations of the words, for example“comprising” and “comprises”, means “including but not limited to”, andis not intended to (and does not) exclude other moieties, additives,components, integers or steps.

Throughout the description and claims of this specification, thesingular encompasses the plural unless the context otherwise requires.In particular, where the indefinite article is used, the specificationis to be understood as contemplating plurality as well as singularity,unless the context requires otherwise.

Features, integers, characteristics, compounds, chemical moieties orgroups described in conjunction with a particular aspect, embodiment orexample of the invention are to be understood to be applicable to anyother aspect, embodiment or example described herein unless incompatibletherewith.

1. A controller for a vehicle, the controller operable to controlcharging of at least one battery that powers one or more electricpropulsion motors in dependence on a location of the vehicle and a timeof day, wherein the controller is operable to determine if the locationof the vehicle corresponds to one or more prescribed locations, and, ifthe location of the vehicle does correspond to one or more prescribedlocations, to perform charging during one or more prescribed periods ofthe day, and wherein the controller is operable to determine if the atleast one battery will be sufficiently charged during the one or moreprescribed periods of the day, and, if the at least one battery will notbe sufficiently charged during the one or more prescribed periods of theday, to commence charging in advance of the one or more prescribedperiods of the day.
 2. The controller of claim 1, wherein the controlleris operable to commence charging in advance of the one or moreprescribed periods of the day to enable the battery to be chargedsufficiently by the end of the prescribed period.
 3. The controller ofclaim 1, wherein the controller is operable to determine that the atleast one battery will be sufficiently charged when the at least onebattery is substantially fully charged.
 4. The controller of claim 1,wherein the controller is operable to determine that the at least onebattery will be sufficiently charged when the at least one battery issufficiently charged for a next journey.
 5. The controller of claim 1,wherein if the location of the vehicle does not correspond to one ormore prescribed locations, the controller is operable to performcharging irrespective of the time of day.
 6. The controller of claim 1,operable to allow a user manually to input data corresponding to anidentity of the one or more prescribed periods of the day when chargingmay be performed at the one or more prescribed locations.
 7. Thecontroller of claim 1, operable to access data corresponding to anidentity of the one or more prescribed periods of the day when chargingmay be performed at the one or more prescribed locations.
 8. Thecontroller of claim 1, arranged to access data in respect of the one ormore times of day during which charging may be performed via oneselected from amongst a wireless internet connection, a mobiletelecommunications network and a portable data storage device.
 9. Thecontroller of claim 1, arranged to receive data indicative of a locationof the vehicle.
 10. The controller of claim 1, comprising a locationdetermination device operable to determine a location of the vehicle.11. The controller of claim 1, operable to charge the at least onebattery to a prescribed value of state of charge over one or more timeperiods determined responsive to data in respect of an expecteddeparture time of the vehicle, the controller being configured tooptimize charging to the prescribed value by charging the at least onebattery for as long as possible during the one or more prescribedperiods prior to the expected departure time.
 12. The controller ofclaim 11, operable to receive an input corresponding to an expecteddeparture time of the vehicle from an operator of the vehicle.
 13. Thecontroller of claim 12, operable to receive the input corresponding toexpected departure time via an input device, the input device being oneselected from amongst a control button and a touchscreen.
 14. Thecontroller of claim 11, operable to determine an expected departure timeresponsive to historical data in respect of vehicle departure times,vehicle departure times from a given location, and/or vehicle departuretimes as a function of day of the week.
 15. The controller of claim 1,operable to allow a user manually to override the controller, such thatwhen the location of the vehicle corresponds to a prescribed locationthe controller performs charging during a non-prescribed period of theday.
 16. A motor vehicle comprising the controller of claim
 1. 17. Anelectric or hybrid electric vehicle comprising the controller ofclaim
 1. 18. A method of controlling charging of at least one battery ofa vehicle that powers one or more electric propulsion motors, the methodcomprising: determining whether a location of the vehicle corresponds toa prescribed location; if the location of the vehicle does correspond toone or more prescribed locations, performing charging of the at leastone battery during one or more prescribed periods of the day;determining if the at least one battery will be sufficiently chargedduring the one or more prescribed periods of the day; and if the atleast one battery will not be sufficiently charged during the one ormore prescribed periods of the day, commencing charging in advance ofthe one or more prescribed periods of the day.
 19. The controller ofclaim 1, wherein if the location of the vehicle corresponds to one ormore prescribed locations the controller is operable to perform chargingduring one or more periods for which the current value of an electricitytariff corresponds to a prescribed one or more values.
 20. Thecontroller of claim 19, wherein the prescribed one or more values of theelectricity tariff corresponds to an off-peak tariff.